Cartridge Emulator's

[16VGTIDave]

As we all know, the front forks on our bikes are crap. That is to be expected from a 30+ year old entry level bike. Most of the fork modifications I've seen people do here are for looks rather than function. Since I'm more interested in function, I've been researching possible fork upgrades for over the winter. For the front forks, other than outright replacement (a consideration that would exceed my budget to complete), there are limited options. Changing the springs, changing the oil viscosity and volume, the infamous 'Minton mods'. And, of course, cartridge emulators. Developed by the folks at RaceTech.com, and shamelessly copied by MikesXS and affiliates. It looks like the cartridge emulators are a cost effective option for adding adjustability and better suspension performance, especially if other mods are performed.

Has anyone run either the RaceTech or MikesXS emulators?

Thanks,
Dave

 

[motoTrooper]

I've done emulators on three of my bikes, the latest being the XS. That said, I haven't had any handling issues. I would like to do direct comparisons between identical bikes with and without them. But when you install them you are directed to cut off some spring coils and offset them with longer top spacers as the suspension can now work 'properly' without the soft springs having to compensate for the damping rod business. I'll admit to not being a professional hand at riding despite my decades of experience, so my subjective perspective may not mean a hill of beans.

But they do seem to allow a firmer spring setup whilst providing supple damping which is what they advertise, I guess…

Time to get on a track!

 

[Unkle Crusty]

My XS400 handles better than my XS11, but most anything else does. The XS11 is a 556 pound tank, or rolling couch depending on the view. The bigger bike needs a fork brace which I have. The steering head bearings also need to be in good condition. Mine are new.
I have gone the heavier oil and more of it route. I am working my way to saying, some of the XS11 guys have installed emulators and like them. I have considered doing the same. But I also bolt on a side car now and then, which is why I have the Mack truck type approach.
Both the front and rear of my XS400 was a bit stiff the other day at minus 6 C. About 25F.
I have not pushed the 400 hard enough, to have an opinion about a fork brace.
Meantime mine is a lot better now that the hinge in the middle has been removed.
The bikes are a nice weight, to be able to work with, and feel the changes.
Please report back on how it goes.

I just got back from the Number 20 store with a length of PVC pipe. Velocity stacks building soon.

Unkle Crusty*

 

[16VGTIDave]

Thanks for the replies guys. I have to admit I'm not surprised by the lack of replies. It seems people either don't do anything internally with their forks, or a few intrepid people replace them with more modern ones. Other than chopping the springs to lower the bike, modifying the stock forks doesn't seem to happen.

Anyways, I've been brainstorming options that will require research, but may be interesting if it all works. That is a big IF! But here goes:

First option - Replace forks with late production XS650 forks, brakes, etc. Then rebuild/upgrade the forks with cartridge emulators, springs, and possibly longer tubes.

Second option - Replace the XS400 fork tubes with longer ones. The later ('77-'84) XS650 used 35mm x 23" long fork tubes, the same diameter that the XS400 Maxim and Seca used, I don't know the XS400 tube length yet.

Third option - Replace the forks with 36 or 37mm forks from another bike. The triple's would have to be machined to fit the larger tubes, but there is enough material there so this shouldn't be an issue. Front wheel and brake would also have to be changed. The replacement forks would likely need emulators and springs. For example, the Kawasaki KL250 Super Sherpa has 36mm forks with 230mm (9.1") of travel and uses a 21" spoke wheel.

Points of interest:
- MikesXS offers XS650 tubes that are 2", 4", or 6" longer than the stock 23". The fork travel isn't changed by this length increase, but the longer tubes would raise the front and provide more ground clearance for the engine, which I'd like. Rough measurements suggest the 2" longer tubes may be adequate (assuming the XS400 tubes are the same 23" length as the XS650), but that has yet to be decided. I'd also have to buy top caps and other bits as the XS650 uses different parts. I don't yet know if the fork internals are interchangeable.

- MikesXS offers knock-off cartridge emulators for the XS650 at 1/3rd the price of genuine RaceTech emulators. If they work well, this will help stay within the budget.

- MikesXS offers progressive XS650 springs, but they are almost 8cm (3 1/4") shorter than the stock XS400 springs. Not sure what the deal is with that yet.

- Better brake disks are available for the XS650, if required. Doubtful, but nice to have options in the future.

 

[motoTrooper]

This is essentially what I've done. I used the front end of my SR500 and put it on the XS400. Steering stems are the same and for my '79 XS it was a step up from 33mm forks to 35mm and the ability to dual disk it. Also the triples are beefier. The SR500 forks are longer which gave me options. I bought the Mikes'XS emulators and had some spare correct Racetech emulator springs from a prior build. I used the Racetech springs as they were probably a higher standard than the chinese copies.

 

[Unkle Crusty]

Moto, what you said in your earlier post about a comparison. I was thinking the same.
If I compare my XS400 to my XS11 it handles fine. And even comparing it to a lot of other bikes it is fine. This may be the case with most owners. They work fine, and if an owner has not been on a newer better handling bike, there is nothing to compare.
For me, I also have an SV1000 Suzuki, with excellent suspension. I felt it was initially a bit soft. New tyres with harder centers fixed it for me.
So a critical look at my XS400 reveals. Not much in the way of progressive damping, front and rear, chain jerk when shifting at high revs, a kind of a clunk from either the forks or steering head, from heavy braking at slower speeds. New tyres next year should help a bit, and I will install new steering head bearings.

I will pay attention to what you guys are doing. Unkle Crusty*

 

[drewpy]

I took my tracker onto a cart track this year. did the heavier fork oil and more of it.

It performed really well and even went faster than my mate on his DOHC bike.

being higher off the ground I had lots of ground clearance. the only issue was the chen shin tyres i had on

 

[motoman1979]

Thanks for the replies guys. I have to admit I'm not surprised by the lack of replies. It seems people either don't do anything internally with their forks, or a few intrepid people replace them with more modern ones. Other than chopping the springs to lower the bike, modifying the stock forks doesn't seem to happen.

Anyways, I've been brainstorming options that will require research, but may be interesting if it all works. That is a big IF! But here goes:

First option - Replace forks with late production XS650 forks, brakes, etc. Then rebuild/upgrade the forks with cartridge emulators, springs, and possibly longer tubes.

Second option - Replace the XS400 fork tubes with longer ones. The later ('77-'84) XS650 used 35mm x 23" long fork tubes, the same diameter that the XS400 Maxim and Seca used, I don't know the XS400 tube length yet.

Third option - Replace the forks with 36 or 37mm forks from another bike. The triple's would have to be machined to fit the larger tubes, but there is enough material there so this shouldn't be an issue. Front wheel and brake would also have to be changed. The replacement forks would likely need emulators and springs. For example, the Kawasaki KL250 Super Sherpa has 36mm forks with 230mm (9.1") of travel and uses a 21" spoke wheel.

Points of interest:
- MikesXS offers XS650 tubes that are 2", 4", or 6" longer than the stock 23". The fork travel isn't changed by this length increase, but the longer tubes would raise the front and provide more ground clearance for the engine, which I'd like. Rough measurements suggest the 2" longer tubes may be adequate (assuming the XS400 tubes are the same 23" length as the XS650), but that has yet to be decided. I'd also have to buy top caps and other bits as the XS650 uses different parts. I don't yet know if the fork internals are interchangeable.

- MikesXS offers knock-off cartridge emulators for the XS650 at 1/3rd the price of genuine RaceTech emulators. If they work well, this will help stay within the budget.

- MikesXS offers progressive XS650 springs, but they are almost 8cm (3 1/4") shorter than the stock XS400 springs. Not sure what the deal is with that yet.

- Better brake disks are available for the XS650, if required. Doubtful, but nice to have options in the future.

So...what did you end doing? I'm thinking of upgrading the front suspension on my '79 xs400 and am looking for some ideas!!

 

[16VGTIDave]

As of today, nothing more than changing the fork oil to synthetic and installing a preload spacer.

And riding the bike.

 

[motoman1979]

As of today, nothing more than changing the fork oil to synthetic and installing a preload spacer.

And riding the bike.

Did those changes make enough difference? What weight of fork oil did you use? 15w? What size of a spacer did you put in? Like pvc pipe?

I definitely need to do something to my front forks...they're way too soft!!

 

[16VGTIDave]

I stayed with 10wt oil as I ride in cold weather. I tried 15wt. It was too stiff for my needs, transmitting every little bump and acting like it was locked up on harder hits. The 15wt was brutally harsh in the cold, even using synthetic oil. The spacers were turned on a lathe from solid plastic stock.

As for being "enough", no they were only improvements that made the forks tolerable. Changing the springs and adding emulators might be enough. But how much do you want to invest in a poor design? Like the old saying goes: Putting lipstick on a pig doesn't make the pig pretty. You'd be better off finding a sheep...

 

[xschris]

Remember the sohc xs400 only has 33mm forks. I run 20w spectro fork oil (what they call for) in all my bikes (with stock forks) with no issues. Have you serviced them yet? If you have never done it I would try that first.

 

[Jeff0133]

Dave,watch yourself with sheep....baaaaah means NO...at least that is what the judge told me....